MMM-Button white screen

I have installed the MMM Button. When I restart my PI3 I only get a white screen.
When I uncomment the butten module in the config with //, the screen is after a new start normal.
I have also tried it with a connected and unconneted butten. Always the same.

@strawberry-3.141
I checked the double checked the spelling. Everthing is correct.
The screen stays white…

I tried node serveronly

pi@raspberrypi:~/MagicMirror $ node serveronly
Loading config …
Loading module helpers …
No helper found for module: alert.
No helper found for module: clock.
Initializing new module helper …
WARNING! Could not find config. Please create one.
Loading module helpers …
No helper found for module: alert.
No helper found for module: clock.
Initializing new module helper …
Whoops! There was an uncaught exception…
{ Error: Cannot find module 'onoff’
at Function.Module._resolveFilename (module.js:440:15)
at Function.Module._load (module.js:388:25)
at Module.require (module.js:468:17)
at require (internal/module.js:20:19)
at Object. (/home/pi/MagicMirror/modules/MMM-Button/node_helper.j s:10:14)
at Module._compile (module.js:541:32)
at Object.Module._extensions…js (module.js:550:10)
at Module.load (module.js:458:32)
at tryModuleLoad (module.js:417:12)
at Function.Module._load (module.js:409:3) code: ‘MODULE_NOT_FOUND’ }
MagicMirror will not quit, but it might be a good idea to check why this happene d. Maybe no internet connection?
If you think this really is an issue, please open an issue on GitHub: https://github.com/MichMich/MagicMirror/issues

That tells me you didn’t read the instructions, because step 2, under Installation, it specifically says to run 'npm install' which would’ve taken care of installing onoff for you. I find it helps when I follow the author’s instructions.

I read the instruction and I executed the nmp install in the MagicMirror folder and thought that onoff would be installed automaticly.
But I had to execute npm install onoff extra in the MagicMirror folder to get the module run.

Maybe there should a step 3, that tells you to execute npm install onoff.